Now Look What You've Done
Stephan Pastis (2014)
Actually haven't finished it yet, but really enjoy it so far. I don't think there's any other book character I've wanted to give a hug to more than Timmy, but I doubt he'd accept one. "Mendacity!"
Not as sad as the first one, but the Calvin and Hobbes-esque (totally a compliment) detective duo is still frustrated in their efforts at Greatness. And solving any case.